Usage has increased but use is still very uncommon in college. My observation has been the older, more elite the play the fewer masks present. Could be they do not want the stigma attached, they do not need them, or both.
IDK, there was a time hockey goalies didn't wear masks.
MLB catcher gear has evolved quite a over the last century +
I'm sure stigma of wearing a mask and the attitude that I've never worn one before have a lot to do with it.
I think rules like dantay17 describe will become more and more common as time goes by.